#include <iostream>

using namespace std;
class Mutex
{
public:
    Mutex(pthread_mutex_t *mtx) : pmtx_(mtx)
    {
    }
    void lock()
    {
        pthread_mutex_lock(pmtx_);
    }
    void unlock()
    {
        pthread_mutex_unlock(pmtx_);
    }
    ~Mutex()
    {
    }

private:
    pthread_mutex_t *pmtx_;
};
class lockGuard
{
    lockGuard(pthread_mutex_t *mtx) : mtx_(mtx)
    {
        mtx_.lock();
    }
    ~lockGuard()
    {
        mtx_.unlock();
    }

private:
    Mutex mtx_;
};